The Basics


Butterflies and moths are two evolutionarily related group of insects. They are in the Lepidoptera.  All of them have wings covered with scales. Their family name comes from the words for scaly (lepido) and winged (ptera).

Most butterflies are very colorful and usually active exclusively during the day. In contrast, most moths are fairly drably colored and are active at night.


One of the first butterfly and moth drawings


The best way to distinguish moths and butterflies is to look at their antennas. Butterfly antennas are a long shaft that has a “club” at its end.


Typical butterfly filament antennae


Most moths have antennas that are fuzzy.  They are either simple filaments, tapering to a point, or are very complicated looking somewhat like radar antennas !


Large moth with “fuzzy” antennae


The species


There are approximately 20,000 species of butterflies in the world.  About 725 species occur in North American north of Mexico.  Roughly 100 species of butterflies are found in and around us in New York City.


Common Buckeye of New England




An adult butterfly has an average life-span of approximately one month. The smallest butterflies may live only a week or so.  Large migrating ones, such as Monarchs and Mourning Cloaks, can live up to nine months.




About half of most butterflies that live in cold climates spend the winter as caterpillars.  Those that hibernate, initiate their response when temperatures go below 50°F. By the time winter hits hardest, the water in the caterpillar’s body has all been moved to the outer cells.  This creates a protective coating that insulates the internal cells from freezing. If ice does form inside there, the caterpillar’s survival is compromised.



Caterpillar ready to hibernate for winter


Almost as many species of butterflies and moths spend the winter as pupas. A few species, spend the winter as adults, hibernating in holes in trees.  They also hide in crevices in man-made structures, or in other shelters.  A fraction of species spend the winter as eggs.


Hibernating chrysalis almost ready to emerge


Summer Migration


Many butterflies that spend the summer in temperate North America cannot survive freezing winters. They spend the cold winters in warmer areas. Each year, as the weather in the north warms up, butterflies from Mexico and the southern United States fly up.  The newly arriving adults repopulate these regions. For most species, this northward dispersal is somewhat gradual.


Butterflies migration Northward in warmer weather


Winter Migration


To us, the reverse migration, south in the fall, is more obvious. However, exactly where all of these species go to is not very well known.

Monarch butterflies are probably the best studied.  They are the most well-known of the migratory butterflies. But even here the knowledge is limited. Most of the Monarchs from west of the Rocky Mountains spend the winter along the California coast.  Those from central North America spend the winter in roosts in the mountains of central Mexico.


Winter migration of Monarch butterfly


If you wants lots of butterflies – like this common NYC butterfly – in your garden next summer

call Plant Specialists today !

We can install the plants that attract them !

White Admiral




Article written by our Staff Horticulturist, Peter B Morris, BSc, MSc, MBA

All photographs used with permission @SHUTTERSTOCK